I hate cows, I once got followed by a load when I was crossing through a field. They all start walking towards you in that horrible zombie movie type way and stare at you all funny.
Horses are more apt to run away from you, though, and NOT trample you. Cows just don't care. Stampeding horses will try to jump over you; stampeding cows will turn you into mulch.
My experience with horses in fields was different to that. They walked up behind me and started banging into me, and trying to stamp on my dog. Miserable twats.
Then they stood at their gate, watching me for ages as I walked away. Creepy bastards.